In an effort to convince Americans to support his demand for a $5.7 billion wall on the Southern border, President Donald Trump cited the murder of Indian origin policeman Ronil Ron Singh in California allegedly by an illegal immigrant.

Trump on Tuesday described the 33-year-old Corporal Singh, a national "hero", saying America's heart broke the day the young officer was "savagely murdered" in cold blood by an "illegal alien".

"America's heart broke the day after Christmas when a young police officer in California was savagely murdered in cold blood by an illegal alien (who) just came across the border. The life of an American hero was stolen by someone who had no right to be in our country," Trump said.

The Californian police have arrested 33-year-old illegal immigrant from Mexico identified as Gustavo Perez Arriaga on charges of killing Singh.

In his first TV address from the Oval Office, the president made a case for building a wall along the Mexico border. He said precious lives were cut short repeatedly by those who have violated the borders.

"In California, an air force veteran was raped, murdered, and beaten to death with a hammer by an illegal alien with a long criminal history. In Georgia an illegal alien was recently charged with murder for killing, beheading and dismembering his neighbor. In Maryland, MS-13 gang members who arrived in the United States as unaccompanied minors were arrested and charged last year after viciously stabbing and beating a 16-year-old," he said.

Trump said over the last several years, he has met with dozens of families whose loved ones were killed by illegal immigration.

"I've held the hands of the weeping mothers and embraced the grief-stricken fathers. So sad. So terrible. I will never forget the pain in their eyes, the tremble in their voices and the sadness gripping there. So how much more American blood must we shed before Congress does its job," he said.

"This is a choice between right and wrong; justice and injustice. This is about whether we fulfill our sacred duty to the American citizens we serve," Trump said.

The president alleged that the Democrats in Congress had been unsuccessful to acknowledge the crisis and refused to provide the border agents with the tools they desperately need to protect families and the nation.

"The federal government remains shut down for one reason and one reason only because Democrats will not fund border security," he alleged.

Noting that his administration was doing everything in its power to help those impacted by the situation, Trump said the only solution was for Democrats to pass a spending bill that defends the borders and reopens the government. "This situation could be solved in a 45-minute meeting," he said.

Calling the immigration matter "a crisis of the heart and soul", Trump said the U.S. is "out of space" to accommodate illegal migrants, adding that it "strains public resources and drives down jobs” that “hurt all Americans."

Trump plans a personal visit to the Mexican border on Thursday as he tries to put pressure on newly empowered Democrats in the shutdown standoff.

As the government shutdown enters its 18th day, Trump has refused to back down on his demands of approval of $5.7 billion to fund the steel wall on the southern border, a request denied by the Democrats.

Trump has invited congressional leaders to the White House Wednesday to find a solution. "Hopefully, we can rise above partisan politics in order to support national security," he said. Observing that some people have suggested that a barrier is immoral, Trump asked why do wealthy politicians build walls, fences, and gates around their homes.

"They don't build walls because they hate the people on the outside, but because they love the people on the inside. The only thing that is immoral is the politicians to do nothing and continue to allow more innocent people to be so horribly victimized," Trump said.